Marine Propulsion & Auxiliary Machinery

Alternative fuel options in a post-diesel world

The engine top of an MAN B&W ME-LGIM methanol engine on one of Methanex’ methanol-fuelled tankers (credit: Methanex)

A handful of alternative power sources look set to propel the shipping industry into the second half of the 21 century, as increasing regulation sounds the death knell for diesel

Hydrogen gets ready for take-off

Hydrogen is the most basic element in the universe. With an atomic number of 1, it is ranked first in the periodic table of the elements and, since the middle of 2017, the prospect of hydrogen becoming a mainstream marine fuel has been lifted by a number of other ‘firsts’.

In November last year, for example, a 14-m high-speed catamaran built by BWSeaCat of the UK became the first Lloyd’s Register-classed vessel to use hydrogen to power a diesel engine. It is used in a dual-fuel system based around a pair of Volvo Penta D4 engines that were retrofitted with a hydrogen injection system to power a crew boat for Belgium’s CMB.

It is called Hydroville and will be used to carry CMB’s staff to and from its Antwerp offices during their morning commute, although the operator has grander long-term plans. In a PowerPoint presentation to mark the vessel’s delivery, CMB research & development manager Roy Campe described the project as “a showcase for the use of a clean fuel in maritime propulsion.” He hopes it will “inspire the industry, attract innovative talent and roll out hydrogen technologies on CMB’s seagoing ships.”

He explained that diesel fuel is still needed to burn the hydrogen, which is injected via the engines’ intercoolers. The engines’ emissions are reduced in proportion to the amount of hydrogen used, with the ratio of the two fuels depending on the engines’ load and speed.

For Lloyd’s Register (LR), the project presented a challenge because “the novel concept of hydrogen-injected diesel engines are not covered by standard LR rules,” said LR global head of engineering systems Ed Fort in a statement last December. Instead, a risk-based design approach to approval was used.

A larger project, called HySeas III, started on 1 July this year to build the world’s first seagoing car and passenger ferry fuelled by hydrogen. It will use fuel cells, rather than internal combustion engines, to convert the hydrogen’s energy to electricity. The vessel will operate in and around Orkney in northern Scotland, using hydrogen that is already being produced using otherwise-wasted energy from windfarms, prompting its backers to describe it as “marking a paradigm shift towards entirely emissions-free marine transport.”

HySeas III intends to build the world’s first seagoing car and passenger ferry fuelled by hydrogen, using fuel cells, rather than internal combustion engines, to convert the hydrogen’s energy to electricity

Those backers are led by Scotland’s Ferguson Marine Engineering and the University of St Andrews, which jointly coordinated a European consortium in a bid for EU funding to support to the ferry’s design and construction. Its development is expected to cost around €12.6M (US$14.6M) of which €9.3M has been awarded by the European Union’s Horizon 2020 research and innovation fund. Marine Propulsion has been advised by a source with experience of EU-funded maritime projects that the UK’s departure from the EU next March is unlikely to affect the project, despite its UK-based leader.

Details of the project were presented at the Smart Shipping Symposium in May, hosted by the City of Glasgow College Faculty of Nautical Studies. Delegates heard that the project’s initial objective is to construct and prove the vessel’s modular drive train onshore and test it for stress and durability using real-world data from existing vessels.

Ferguson Marine Engineering chief naval architect Chris Dunn highlighted some of the practical challenges that the ferry and the project faces. He told Marine Propulsion that there are few published rules or standards on using hydrogen as a marine fuel “so we will need to work extensively with [the regulators] through an intensive risk-based design process to achieve the necessary approvals.”

He also noted that there are no standard bunkering interfaces for hydrogen and the poor power density for hydrogen requires large gas storage tanks.

Meanwhile, in Norway, three ferry operators have been invited to submit material ahead of preparing a bid to provide a ferry link on the country’s west coast, to start in 2021. In May this year, the Norwegian Public Roads Administration (NPRA) asked operators Boreal Sjø, Fjord1 and Norled to contribute to the dialogue phase of a project that will lead to what is said to be the world's first hydrogen-electric ferry, using fuel cells to operate a triangular service between Hjelmeland, Skipavik and Nesvik in Norway’s Rogaland region.

NPRA has specified that the route should be operated with at least 50% hydrogen energy, with the rest coming from the electricity network, charging batteries at the loading berths. NPRA project manager Camilla Røhme described the scheme as “a demanding development. Very few components in a hydrogen system are certified for maritime use,” she said, and paid tribute to the “impressive work … done by the shipping companies and the supplier industry.”

In the US, a fuel cell-powered ferry is due to enter service next year after Golden Gate Zero Emission Marine (GGZEM) was awarded a US$3M grant by the California Air Resources Board (CARB) in June. It will be the first commercially-operated hydrogen fuel cell ferry in the world, GGZEM states on its website. Its fuelling arrangements will allow the ferry, to be named, Water-Go-Round, to be fuelled anywhere with truck access.

The aluminium catamaran, designed by Incat Crowther, will have a 22-knot top speed and be built by Bay Ship & Yacht Co of Alameda, California. It will be powered by dual 300-kW electric motors using independent electric drivetrains from BAE Systems. Power will be generated by 360 kW of Hydrogenics proton exchange membrane fuel cells and Li-ion battery packs. Hydrogen tanks will be installed on its upper deck and contain enough hydrogen for up to two days between refuellings.

It will initially be operated by Red and White Fleet for a three-month trial period in San Francisco Bay. The operator plans then to purchase the vessel as the first of several vessels to meet its commitment to a zero-emission operation.

Hydrogen: a sustainable future fuel

Much of this feature is devoted to hydrogen over the other fuels under review – methanol and nuclear – because it was identified earlier this year as one of three fuelling options that could lead to zero-emission vessels (ZEVs).

A report published in May by Lloyd’s Register and the UK-based University Maritime Advisory Services for the Sustainable Shipping Initiative (SSI) selected hydrogen, electricity and biofuels as the best candidates to power ZEVs because “they can feasibly replace a conventional ship with limited impacts to voyage times, routes or cargo-carrying arrangements [and] they all produce only trace greenhouse gas (GHG) emissions under continuous operation.”

The report, Zero Emission Vessels, what needs to be done? includes discussion about hydrogen, focusing on fuel cells rather than internal combustion engines. But it acknowledged that producing hydrogen is expensive, fuel cells are only about 40% efficient and storage options for liquid hydrogen are not as developed as those for other gasses.

In the long term, fuel cells will become about 75% efficient and “only green hydrogen with nearly zero CO2 emissions [during its production] is used in shipping,” the paper notes in a summary of one of its forecast scenarios.

In its conclusions, however, hydrogen and electric power are both ranked behind biofuel in the quest for ZEVs. “For hydrogen fuel cell options, the associated costs of the technology on board (both hydrogen storage and the fuel cell) weigh significantly on the overall profitability,” the report states. But it also briefly mentions internal combustion engines, suggesting that producing hydrogen by “electrolysis with renewable electricity can also be used to produce ammonia … which is less costly to store on board. Both hydrogen and ammonia can be used directly in internal combustion engines, which can also help control capital costs.”

Voyage costs, however, “remain the largest contributory factor to the poor competitiveness of hydrogen fuel cells,” it adds, although there is “great potential for [cost] reduction, even within the timescales used in this study- out to 2030.”

Class societies home in on fuel cells and methanol

Class societies are focusing on the use of new alternative power sources within passenger shipping.

Stena Germanica was the first significant ship to operate on methanol when it was converted in 2015 (credit: Stena Line)

Bureau Veritas (BV) global market leader, passenger ships and ferries Andreas Ullrich – appointed to the position in March this year – told Marine Propulsion’s sister publication Passenger Ship Technology “New technologies such as fuel cells are, I think, the future.”

BV has classed and is classing some ground-breaking alterative power newbuild projects, including a number of LNG-fuelled projects, including Seapsan’s LNG battery-hybrid ferries. This gave the society “a lot of experience” with hybrid technology, Mr Ullrich said, prompting it to update its energy storage systems (ESS) rules in July last year with a new chapter providing a framework for electric and hybrid power solutions. The new class notations include power management, power back-up and zero-emission standards.

Lloyd’s Register (LR) is also looking at alternative fuels, including fuel cells and hydrogen. It has taken a leading role investigating alternative fuels for passenger ships as it classed the methanol conversion of Stena Germanica in 2015, making it the first significant vessel to operate on methanol.

As for hydrogen, LR’s global sustainability manager Katharine Palmer told Marine Propulsion that although interest in using it as a marine fuel is increasing, “the economics for the internationally-trading fleet do not seem viable due to the relatively poor volumetric energy density, worldwide availability and lifecycle economics, although we are researching how this could change in the future.”

Methanol can be a cost-effective alternative marine fuel that is available worldwide through existing infrastructure

On some specific routes, such as short inshore and inland operations on defined restricted routes where onboard energy demands are relatively low and bunkering is frequent, hydrogen can be viable now in the short term.

RINA is another class society involved with methanol and fuel cells for the ferry and cruise industry. RINA executive vice president for marine strategic development Paolo Moretti sees potential in methanol as an energy source for fuel cells, describing it as “the low-hanging fruit. [It is] liquid, ready for use without excessive pressure, has no cryogenic problems [and minimal] impact on the payload of the ship.”

He said methanol can be a cost-effective alternative marine fuel that is available worldwide through existing infrastructure. “With the growing demand for cleaner marine fuel, methanol is a promising alternative fuel to help the shipping industry meet increasingly strict emissions regulations,” Mr Moretti commented. In addition, converting a ship to run on methanol is “significantly less” than alternative fuel conversions, he said.

RINA has been actively involved in co-ordinating national experts and providing input to the IMO correspondence group on the “Amendments to the IGF Code and development of guidelines for low-flashpoint fuels”. The group is working towards a completion date in September, as this issue of Marine Propulsion is published.

It will be backed-up by the Interim Guidelines for ships using methyl/ethyl alcohol as fuel that will provide guidance for the arrangement, installation, control and monitoring of machinery, equipment and systems using those fuels to minimise the risk to the ship, its crew and the environment.

In January of this year RINA issued its own rules for fuel cell installations in ships, which Mr Moretti said were consistent with the developing international regulatory framework. “Consequently, only minor adjustments may be expected in the future, mostly triggered by the feedback from ongoing R&D projects or newbuilding activities,” he said.

MSC meeting calls for new methanol fuel standards

Methanol took a step towards widespread use in June when the 99th meeting of IMO’s Maritime Safety Committee (MSC 99) asked the International Organization for Standardization (ISO) to develop a standard for methyl/ethyl alcohol as a marine fuel and another standard for the couplings needed to handle it.

An ISO observer at the meeting said the organisation would be willing to develop these standards but highlighted a difficulty, pointing out to delegates that there was insufficient use of such a fuel (which is normally required for a technology before ISO will develop a standard) and the industry was short of experience.

In response, the Cook Islands delegation proposed that appropriate IMO legislation should be developed prior to the development of the ISO standards, which it said should take into account the safety concerns associated with the low flashpoint and volatile nature of methyl/ethyl alcohol as a marine fuel. IMO’s report on MSC 99 said that the meeting ‘noted’ those comments, but that “does not mean that the Cook Islands’ proposal was accepted or agreed,” its secretariat advised Marine Propulsion.

MSC 99’s decision was welcomed by the Methanol Institute (MI). In a statement on 9 July it said the development “reflects growth of interest in methanol as a safe, clean marine fuel”. Its statement included comments by the International Bunker Industry Association’s IMO representative, Unni Einemo, who explained that ISO’s involvement at this stage is unusual. “ISO has traditionally developed fuel standards only after user experience to be able to assess which parameters need to be specified and what relevant limits should be [set],” he said.

The International Methanol Producers and Consumers Association has already established a specification that is widely used by producers and consumers, but “a dedicated ISO standard will help shipowners understand the fuel in a marine fuel context,” said MI chief operating officer Chris Chatterton in the statement.

He reported “increasing interest around methanol as a liquid fuel that is safe to handle, easy to ship and store and is more widely available than other low sulphur alternatives.”

So far, there are only eight ships operating on methanol: the ropax Stena Germanica and seven tankers operated by Waterfront Shipping, which has four more on order and due for delivery next year.

Waterfront is the shipping arm of Methanex, the world’s largest producer and supplier of methanol, which can be made from LNG or natural resources, making it a “long-term sustainable fuel” that is available around the world, according to a company video on Methanex’ website.

Lloyd’s Register global passenger ship manager John Hicks pointed out that a benefit over other alternative fuels is that it “can be put into a normal tank [that] does not have to be a Type-C or cryogenic tank.”

Lloyd’s Register (LR) has already published provisional rules for classifying methanol-fuelled ships and the class society’s global sustainability manager Katharine Palmer told Marine Propulsion that the society is involved in IMO’s correspondence group on its International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (known as the IGF Code), which will cover methanol.

That group is expected to finish its work soon, she said in late July. After that, “LR’s provisional rules will be aligned and incorporated as full rules, thereby providing much of the technical details not included in the statutory regulations,” she said.

Interest in nuclear power is ‘quite conceivable’

Nuclear propulsion for merchant ships is not an option that is high on any shipowner’s list of emissions-reducing propulsion arrangements. But that may not always be the case, believes the London-based World Nuclear Association.

In a 7,500-word online article that was updated in July (http://bit.ly/WNA-NShips) about all forms of nuclear-powered shipping, it reviews the chequered history of nuclear-powered commercial vessels but predicts that “with increasing attention being given to greenhouse gas emissions arising from burning fossil fuels … and the excellent safety record of nuclear-powered ships, it is quite conceivable that renewed attention will be given to marine nuclear powered ships.”

The association’s senior communication manager Jonathan Cobb told Marine Propulsion that this prediction is based on more than 60 years of experience of surface and submarine propulsion, which shows “there is great potential for nuclear technologies to offer a low-carbon alternative to fossil fuels.”

This self-contained nuclear reactor is intended for land-use; those proposed for shipping would be similar, but smaller (credit: Korea Atomic Energy Research Institute)

Dr Cobb mentioned increasing Russian use of nuclear propulsion to power icebreakers as a current example of nuclear propulsion and said that Russia had launched its first floating nuclear power plant. This was built in St Petersburg and Marine Propulsion has previously reported that it will be fuelled in Murmansk, from where it will be towed to Pevek, at the eastern end of the Northern Sea Route and the most northerly town in Russia.

It is due to go into service in the middle of next year, generating enough power for a town of up to 100,000 people. Construction of a second is due to start next year. Dr Cobb advised that China is developing vessels that will use nuclear reactors both for propulsion and power supply.

“Public acceptance is often raised as an issue for the use of civil nuclear technologies,” he said, but added that “the future for nuclear propulsion may equally be influenced by the extent to which the fossil fuel emissions of diesel-fuelled shipping will no longer be publicly or politically acceptable.”

The future for nuclear propulsion may equally be influenced by the extent to which the fossil fuel emissions of diesel-fuelled shipping will no longer be publicly or politically acceptable

The economics of nuclear-powered propulsion “can work with a high-enough carbon price,” believes Tristan Smith, a reader at University College London who studies the environmental impacts of shipping.

But responding in May to comments by Marine Propulsion’s executive editor Paul Gunton about the cost-benefit of nuclear powering, Dr Smith said that, because of cheaper hydrogen fuel-cell competitors, “we think it is unlikely to get to the point where nuclear reactors on ships are competitive.”

An even bigger obstacle, however, would be the constraints and treaties required to operate such ships. As an example, he suggested that two nuclear states might allow a jointly managed and operated ship to trade between them, “with a lot of complexity and treaty negotiation around what happens if a leak did occur”, but that it would be unlikely for that ship then to call at a third country. As for tramp ships, “the political nightmare of negotiating a treaty that could cover global operation would be very limited.”

One organisation that has long had an interest in nuclear propulsion is class society Lloyd’s Register. In 2010, it formed a consortium with Enterprises Shipping and Trading, Hyperion Power Generation and BMT to examine the marine applications for small modular reactors.

More recently, in 2013, its Strategic Research Group looked at nuclear options and one of its outcomes was a paper written with academics from Southampton University, Concepts for a modular nuclear-powered container ship. (http://bit.ly/LR-SU-NCS). It proposed a solution to political constraints by avoiding bringing a nuclear-powered ship into a port. Instead, a tug-and-barge design was proposed, with the nuclear propulsion module separating from the ship and remaining in international waters while the cargo module continues, using batteries that had been charged by the nuclear plant.

Lloyd’s Register global head of technology, risk management, Vince Jenkins, told Marine Propulsion in July that the society had been involved in nuclear power since the 1960s, historically driven by the escalating cost of bunker fuel, potential regulation on GHG emissions and concerns over the continuity of bunker supply.

Its interest remains, he indicated. “With the adoption of the IMO GHG strategy and the forthcoming entry into force of the global sulphur cap regulation, these drivers are still valid today and the main reason for industry interest in nuclear power,” he said.